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Microbial etiology of diarrhea is a significant cause of death, especially in children in developing countries. The presence of microbes that are resistant to current treatment options for diarrhea suggests the need to find newer antimicrobial agents for treatment. Therefore, this study focused on investigating the antimicrobial effect of some Ghanaian chewing sticks commonly used for oral hygiene, Azadirachta indica, Garcinia afzelii, and Garcinia kola, against selected diarrhea-causing organisms. From the stem and bark of each plant, 70% methanolic extract was experimented on Salmonella and Shigella species, namely, Shigella sonnei, Shigella flexeneri, Salmonella typhinirium enterica, Salmonella typhi attenuated, and Klebsiella oxytoca for microbial susceptibility using the agar well diffusion method. Additionally, the antioxidant profile of the methanolic extracts were investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, 2,2’-azino-bis (3-ethylbenzthiazoline-6-sulphonic) acid (ABTS) scavenging activities, and ferric-reducing antioxidant potential (FRAP) assays, while the total polyphenolic content was determined using the Folin–Ciocalteau reagent. G. afzelii and A. indica stem demonstrated the highest antimicrobial effect, inhibiting the growth of all test organisms. Additionally, the extracts demonstrated high antioxidant potential and were found to possess significant amounts of phenolic compounds. Therefore, methanolic extracts of G. afzelii and A. indica stem are promising candidates for the identification of safe novel compounds to mitigate diarrheal diseases.

Objective : The aim of this study was to examine the antioxidant, phytochemical and physicochemical properties of sesame seeds grown in Ghana. Methodology : The seeds were extracted in either 70% (v/v) methanol, ethanol or acetone. The antioxidant activity of each extract was investigated using the DPPH, ABTS and FRAP assays. The total phenolic and total flavonoid contents were also investigated. The proximate analysis, as well as the mineral contents of the seeds, were carried out using the wet acid digestion method for multiple nutrient determinations. Results : The acetone extract demonstrated the highest antioxidant activity by scavenging 60.12 % DPPH, 96.45 % ABTS and had a FRAP value of 0.408. This was followed by the ethanolic extract, which quenched 55 % DPPH, 91.91 % ABTS, with a FRAP value of 0.245. The methanolic extract demonstrated the least antioxidant effect by scavenging 51.26 % DPPH, 89.72% ABTS and had a FRAP value of 0.208. The total Phenolic contents strongly correlated with antioxidant activity and were recorded at 99.67, 95.6 and 81.72 GAE/10 µL respectively for the acetone, methanolic and ethanolic extracts. The fat content of the seed was very high, constituting 56.56%. This was followed by carbohydrate (18.44 %), protein (15.67 %) and fibre (8.22%) with low moisture (3.49 %). Magnesium was found to be the mineral with the highest composition (182.47 mg/100g), which was followed by sodium (105.52), iron (7.37) and zinc (4.47) mg/100g. Conclusion : Sesame seeds possess significant antioxidant activity. They also contain significant amounts of phenolics, flavonoids, nutrients and minerals. This suggests that dietary uptake of sesame seeds could be potentially protective against diverse diseases.

This study investigated the antioxidant and antimicrobial effects of the peel, rind, pulp and seeds of C. lanatus (watermelon) as well as their respective phytochemical composition. The antioxidant effect was investigated using the DPPH and ABTS assay whereas the antimicrobial activity was evaluated using the well diffusion and broth dilution methods. The results revealed that the peel possessed the highest antioxidant activity whereas the pulp demonstrated the lowest. The peels demonstrated the highest antimicrobial effect, which was followed by the seed and then the rind. The pulp, however, demonstrated the least antimicrobial activity. A strong correlation was observed between total phenolic contents and biological activity. The peels were found to possess the highest content of total phenolics (0.087±0.002 mgGAE/g), which was followed by the seed (0.042±0.003 mgGAE/g) and the rind (0.026±0.003 mgGAE/g). The pulp did not only demonstrate the lowest antioxidant and antimicrobial activities but also had the lowest phenolic content (0.010±0.001 mgGAE/g). The peel and the seed show the presence of flavonoids whereas alkaloids and free reducing sugars were present in all parts of the watermelon fruit. From the results of the current study, it can, therefore, be concluded that among the various parts of the watermelon fruit, the peel has the highest antioxidant and antimicrobial activity whereas the pulp has the least. The peels and seeds are not only potent in their antioxidant and antimicrobial effects but also possess appreciable levels of phenolic compounds relative to the other parts.